Semiconductor device and method of fabricating the same

Abstract

A method of fabricating a semiconductor device includes: forming alternately a plurality of first films and a plurality of second films on a substrate, forming a hole in the first and second films, forming a first metal layer on a surface of the hole, and removing the first metal layer from a bottom of the hole. The method further includes forming a second metal layer on a surface of the first metal layer after removing the first metal layer from the bottom of the hole. The method further includes processing the bottom of the hole exposed from the first and second metal layers to increase a depth of the hole.

What is claimed is: 
     
       1. A method of fabricating a semiconductor device, comprising:
 forming alternately a plurality of first films and a plurality of second films on a substrate; 
 forming a hole in the first and second films; 
 forming a first metal layer on a surface of the hole; 
 removing the first metal layer from a bottom of the hole; 
 forming a second metal layer on a surface of the first metal layer after removing the first metal layer from the bottom of the hole; and 
 processing the bottom of the hole exposed from the first and second metal layers to increase a depth of the hole. 
 
     
     
       2. The method according to  claim 1 , wherein
 the first metal layer contains at least one of titanium, tantalum, or tungsten. 
 
     
     
       3. The method according to  claim 1 , wherein
 the second metal layer contains tungsten or aluminum. 
 
     
     
       4. The method according to  claim 1 , further comprising:
 removing the first and second metal layers from the hole after increasing the depth of the hole; and 
 forming a conductor layer or a semiconductor layer in the hole after removing the first and second metal layers from the hole. 
 
     
     
       5. The method according to  claim 1 , wherein
 after the depth increases, the hole includes:
 a first side surface having a tubular shape; and 
 a second side surface that is located below the first side surface and has a tubular shape, and 
 
 a seam line disposed between the first side surface and the second side surface. 
 
     
     
       6. The method according to  claim 5 , wherein
 the second side surface has a maximum diameter larger than a diameter at the seam line. 
 
     
     
       7. The method according to  claim 1 , wherein
 the first and second metal layers are formed in a first apparatus, and 
 the forming the hole, the removing the first metal layer from the bottom of the hole, and the processing the bottom of the hole are performed in the first apparatus or a second apparatus different from the first apparatus. 
 
     
     
       8. A semiconductor device comprising:
 a plurality of first films and a plurality of second films that are alternately disposed on a substrate; and 
 a conductor layer or a semiconductor layer that is disposed in the first and second films, wherein 
 the first and second films have a side surface which has a tubular shape and surrounds the conductor layer or the semiconductor layer, 
 the side surface of the first and second films includes:
 a first side surface having a tubular shape, and 
 a second side surface that is located below the first side surface and has a tubular shape, and 
 
 a seam line disposed between the first side surface and the second side surface, a diameter of a bottom of the second side surface is smaller than a diameter of the seam line, 
 wherein the second side surface has a maximum diameter larger than the diameter of the seam line. 
 
     
     
       9. A method of fabricating a semiconductor device, the method comprising:
 forming a film to be processed on a substrate; 
 forming a concave portion in the film to be processed in a chamber; 
 forming a metal layer on a portion of the concave portion in the chamber following the forming of the concave portion; and 
 processing a bottom of the concave portion exposed from the metal layer in the chamber to increase a depth of the concave portion following the forming of the metal layer, 
 wherein the film to be processed comprises a plurality of first films and a plurality of second films that are alternately stacked, and 
 wherein when forming the metal layer, a first metal layer is formed on a surface of the concave portion, the first metal layer is removed from the bottom of the concave portion, and then a second metal layer is formed on a surface of the first metal layer. 
 
     
     
       10. The method according to  claim 9 , wherein
 when forming the second metal layer, a first gas including a metal material of the second metal layer and a second gas for reducing the metal material are alternately supplied into the chamber. 
 
     
     
       11. The method according to  claim 10 , wherein
 the second gas is turned into plasma. 
 
     
     
       12. The method according to  claim 10 , wherein the first gas includes at least one of tungsten (W), molybdenum (Mo), aluminum (Al), titanium (Ti), tantalum (Ta), platinum (Pt), rhenium (Re) or iridium (Ir). 
     
     
       13. The method according to  claim 10 , wherein
 the first gas includes at least one of tungsten hexafluoride (WF 6 ) gas, tungsten hexachloride (WCl 6 ), tungsten hexacarbonyl (W(CO) 6 ), molybdenum hexafluoride (MoF 6 ) gas, molybdenum hexachloride (MoCl 6 ), molybdenum hexacarbonyl (Mo(CO) 6 ), aluminum chloride (AlCl 3 ), trimethylaluminum (Al(CH 3 ) 3 ), titanium tetrachloride (TiCl 4 ), tantalum pentachloride (TaCl 5 ), platinum hexafluoride (PtF 6 ) gas, rhenium hexafluoride (ReF 6 ) gas, or iridium hexafluoride (IrF 6 ). 
 
     
     
       14. The method according to  claim 10 , wherein
 the second gas includes at least one of hydrogen (H), oxygen (O) or nitrogen (N). 
 
     
     
       15. The method according to  claim 10 , wherein
 the second gas includes at least one of hydrogen (H 2 ) gas, hydrogen fluoride (HF) gas, hydrogen chloride (HCl) gas, hydrogen bromide (HBr) gas, water vapor (H 2 O), hydrogen sulfide (H 2 S), hydrogen selenide (H 2 Se) gas, ammonia (NH 3 ) gas, phosphine (PH 3 ) gas, arsine (AsH 3 ) gas, methane (CH 4 ) gas, monosilane (SiH 4 ) gas, disilane (Si 2 H 6 ) gas, diborane (B 2 H 6 ) gas, oxygen (O 2 ) gas, nitrogen (N 2 ) gas, nitrogen monoxide (NO) gas, nitrogen dioxide (NO 2 ) gas, dinitrogen monoxide (N 2 O), carbon monoxide (CO) gas, carbon dioxide (CO 2 ), carbonyl sulfide (COS) gas, sulfur monoxide (SO) gas, or sulfur dioxide (SO 2 ) gas. 
 
     
     
       16. The method according to  claim 2 , further comprising:
 removing the first and second metal layers from the hole after increasing the depth of the hole; and 
 forming a conductor layer or a semiconductor layer in the hole after removing the first and second metal layers from the hole. 
 
     
     
       17. The method according to  claim 3 , further comprising:
 removing the first and second metal layers from the hole after increasing the depth of the hole; and 
 forming a conductor layer or a semiconductor layer in the hole after removing the first and second metal layers from the hole. 
 
     
     
       18. The method according to  claim 11 , wherein
 the second gas includes at least one of hydrogen (H), oxygen (O) or nitrogen (N).